function [f,t]=enframe(x,win,inc)
 %ENFRAME split signal up into (overlapping) frames: one per row. [F,T]=(X,WIN,INC)
 %
 %    F = ENFRAME(X,LEN) splits the vector X(:) up into
 %    frames. Each frame is of length LEN and occupies
 %    one row of the output matrix. The last few frames of X
 %    will be ignored if its length is not divisible by LEN.
 %    It is an error if X is shorter than LEN.
 %
 %    F = ENFRAME(X,LEN,INC) has frames beginning at increments of INC
 %    The centre of frame I is X((I-1)*INC+(LEN+1)/2) for I=1,2,...
 %    The number of frames is fix((length(X)-LEN+INC)/INC)
 %
 %    F = ENFRAME(X,WINDOW) or ENFRAME(X,WINDOW,INC) multiplies
 %    each frame by WINDOW(:)
 %
 %   The second output argument, T, gives the time in samples at the centre
 %   of each frame. T=i corresponds to the time of sample X(i).
 %
 % Example of frame-based processing:
 %          INC=20                                                           % set frame increment
 %          NW=INC*2                                                         % oversample by a factor of 2 (4 is also often used)
 %          S=cos((0:NW*7)*6*pi/NW);                                % example input signal
 %          W=sqrt(hamming(NW+1)); W(end)=[];      % sqrt hamming window of period NW
 %          F=enframe(S,W,INC);                           % split into frames
 %          ... process frames ...
 %          X=overlapadd(F,W,INC);                       % reconstitute the time waveform (omit "X=" to plot waveform)
 
 %       Copyright (C) Mike Brookes 1997
 %      Version: $Id: enframe.m,v 1.7 2009/11/01 21:08:21 dmb Exp $
 %
 %   VOICEBOX is a MATLAB toolbox for speech processing.
 %   Home page: http://www.ee.ic.ac.uk/hp/staff/dmb/voicebox/voicebox.html
 %
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %   This program is free software; you can redistribute it and/or modify
 %   it under the terms of the GNU General Public License as published by
 %   the Free Software Foundation; either version 2 of the License, or
 %   (at your option) any later version.
 %
 %   This program is distributed in the hope that it will be useful,
 %   but WITHOUT ANY WARRANTY; without even the implied warranty of
 %   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 %   GNU General Public License for more details.
 %
 %   You can obtain a copy of the GNU General Public License from
 %   http://www.gnu.org/copyleft/gpl.html or by writing to
 %   Free Software Foundation, Inc.,675 Mass Ave, Cambridge, MA 02139, USA.
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
 nx=length(x(:));
 nwin=length(win);
 if (nwin == 1)
    len = win;
 else
    len = nwin;
 end
 if (nargin < 3)
    inc = len;
 end
 nf = fix((nx-len+inc)/inc);
 f=zeros(nf,len);
 indf= inc*(0:(nf-1)).';
 inds = (1:len);
 f(:) = x(indf(:,ones(1,len))+inds(ones(nf,1),:));
 if (nwin > 1)
     w = win(:)';
     f = f .* w(ones(nf,1),:);
 end
 if nargout>1
     t=(1+len)/2+indf;
 end
 
